Flame-Retardant Structural Adhesive Delo-Duopox AB8162

Lightweight Construction in Aircraft Interiors

Demand for commercial aircraft is booming worldwide. With the new flame-retardant structural adhesive, Delo-Duopox AB8162, Delo Industrie Klebstoffe GmbH & Co. KGaA, Windach, Germany wants to make the production faster. The company has developed its new, two-component epoxy resin especially for lightweight structural joints in aircraft interiors, focusing on fast build-up of strength. The resin cures at room temperature, but has been optimized for temperature-accelerated curing. For example, at a temperature of 60 °C, a curing time of 15 minutes is sufficient to achieve functional strength (>= 10 MPa). Consequently, components can be further processed after this time.

Withstands Heat und Age

The adhesive is multi-purpose, including coating or bonding of insert fasteners. With its beige-yellowish color, it has been visually adapted to honeycomb sandwich panels, which are frequently used in the production of aircraft. Delo-Duopox AB8162 ensures consistently high strengths, even under the influence of both temperature and aging, and features very good resistance to media such as Skydrol, for example. This is a hydraulic fluid that is commonly used in aviation.

Due to the importance of safety, the materials used in aircraft interiors must fulfill high fire protection requirements. Therefore, the structural adhesive is a flame retardant product. It complies with the requirements of FST tests according to CS/FAR Part 25 §25.853 (a)(1)(ii) and those of the Airbus standard ABD0031. FST stands for Flame, Smoke, Toxicity. In these tests, a rod-shaped sample of pure adhesive is held over a Bunsen burner flame for 12 seconds. After this time the adhesive must extinguish itself. It is also required to achieve low flue gas density and a low toxicity level. Further more the adhesive is a CMR-free product (non-carcinogenic / non-mutagenic / non-reprotoxic).

The Automix dispensing system allows the adhesive to be processed just like a one-component product, with its thixotropic properties ensuring excellent flow behavior. When the shear stress stops at the end of the dispensing process, viscosity will increase again, preventing the adhesive from flowing out.